(Ivanhoe Newswire) -- The final results of a clinical trial show adding chemotherapy to radiotherapy treatment for brain tumors can extend a patient's survival for up to five years.

Researchers focused their study on the most common and aggressive brain tumor, glioblastoma. For over 30 years, post-operative radiotherapy was the standard treatment, but only offered modest survival benefits -- about nine months. In the clinical trial, scientists gave patients the chemotherapy drug temozolomide in combination with radiotherapy.

Findings showed at three years, 16 percent of patients receiving the combination treatment were alive compared with only 4 percent of patients who were receiving radiotherapy. At five years, that comparison was nearly 10 percent survival versus a 2 percent survival rate.

The authors noted no difference in the pattern of recurrence between patients who were treated with radiotherapy alone or with the addition of chemotherapy. Researchers caution that while the combined therapy may be effective in reducing tumor bulk and aggressiveness, it is unlikely to lead to a cure.

SOURCE: The Lancet Oncology online edition, March 2009